llvm/test/Transforms/InstCombine/smax-icmp.ll
Sanjay Patel 21b74be87d [InstCombine] add folds for icmp (smax X, Y), X
This is a follow-up to:
https://reviews.llvm.org/rL289855 (D27531)



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290111 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-19 16:28:53 +00:00

235 lines
6.2 KiB
LLVM

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -S -instcombine < %s | FileCheck %s
; If we have an smax feeding a signed or equality icmp that shares an
; operand with the smax, the compare should always be folded.
; Test all 4 foldable predicates (eq,ne,sgt,sle) * 4 commutation
; possibilities for each predicate. Note that folds to true/false
; (predicate = sge/slt) or folds to an existing instruction should be
; handled by InstSimplify.
; smax(X, Y) == X --> X >= Y
define i1 @eq_smax1(i32 %x, i32 %y) {
; CHECK-LABEL: @eq_smax1(
; CHECK-NEXT: [[CMP2:%.*]] = icmp sge i32 %x, %y
; CHECK-NEXT: ret i1 [[CMP2]]
;
%cmp1 = icmp sgt i32 %x, %y
%sel = select i1 %cmp1, i32 %x, i32 %y
%cmp2 = icmp eq i32 %sel, %x
ret i1 %cmp2
}
; Commute max operands.
define i1 @eq_smax2(i32 %x, i32 %y) {
; CHECK-LABEL: @eq_smax2(
; CHECK-NEXT: [[CMP2:%.*]] = icmp sge i32 %x, %y
; CHECK-NEXT: ret i1 [[CMP2]]
;
%cmp1 = icmp sgt i32 %y, %x
%sel = select i1 %cmp1, i32 %y, i32 %x
%cmp2 = icmp eq i32 %sel, %x
ret i1 %cmp2
}
; Disguise the icmp predicate by commuting the max op to the RHS.
define i1 @eq_smax3(i32 %a, i32 %y) {
; CHECK-LABEL: @eq_smax3(
; CHECK-NEXT: [[X:%.*]] = add i32 %a, 3
; CHECK-NEXT: [[CMP2:%.*]] = icmp sge i32 [[X]], %y
; CHECK-NEXT: ret i1 [[CMP2]]
;
%x = add i32 %a, 3 ; thwart complexity-based canonicalization
%cmp1 = icmp sgt i32 %x, %y
%sel = select i1 %cmp1, i32 %x, i32 %y
%cmp2 = icmp eq i32 %x, %sel
ret i1 %cmp2
}
; Commute max operands.
define i1 @eq_smax4(i32 %a, i32 %y) {
; CHECK-LABEL: @eq_smax4(
; CHECK-NEXT: [[X:%.*]] = add i32 %a, 3
; CHECK-NEXT: [[CMP2:%.*]] = icmp sge i32 [[X]], %y
; CHECK-NEXT: ret i1 [[CMP2]]
;
%x = add i32 %a, 3 ; thwart complexity-based canonicalization
%cmp1 = icmp sgt i32 %y, %x
%sel = select i1 %cmp1, i32 %y, i32 %x
%cmp2 = icmp eq i32 %x, %sel
ret i1 %cmp2
}
; smax(X, Y) <= X --> X >= Y
define i1 @sle_smax1(i32 %x, i32 %y) {
; CHECK-LABEL: @sle_smax1(
; CHECK-NEXT: [[CMP2:%.*]] = icmp sge i32 %x, %y
; CHECK-NEXT: ret i1 [[CMP2]]
;
%cmp1 = icmp sgt i32 %x, %y
%sel = select i1 %cmp1, i32 %x, i32 %y
%cmp2 = icmp sle i32 %sel, %x
ret i1 %cmp2
}
; Commute max operands.
define i1 @sle_smax2(i32 %x, i32 %y) {
; CHECK-LABEL: @sle_smax2(
; CHECK-NEXT: [[CMP2:%.*]] = icmp sge i32 %x, %y
; CHECK-NEXT: ret i1 [[CMP2]]
;
%cmp1 = icmp sgt i32 %y, %x
%sel = select i1 %cmp1, i32 %y, i32 %x
%cmp2 = icmp sle i32 %sel, %x
ret i1 %cmp2
}
; Disguise the icmp predicate by commuting the max op to the RHS.
define i1 @sle_smax3(i32 %a, i32 %y) {
; CHECK-LABEL: @sle_smax3(
; CHECK-NEXT: [[X:%.*]] = add i32 %a, 3
; CHECK-NEXT: [[CMP2:%.*]] = icmp sge i32 [[X]], %y
; CHECK-NEXT: ret i1 [[CMP2]]
;
%x = add i32 %a, 3 ; thwart complexity-based canonicalization
%cmp1 = icmp sgt i32 %x, %y
%sel = select i1 %cmp1, i32 %x, i32 %y
%cmp2 = icmp sge i32 %x, %sel
ret i1 %cmp2
}
; Commute max operands.
define i1 @sle_smax4(i32 %a, i32 %y) {
; CHECK-LABEL: @sle_smax4(
; CHECK-NEXT: [[X:%.*]] = add i32 %a, 3
; CHECK-NEXT: [[CMP2:%.*]] = icmp sge i32 [[X]], %y
; CHECK-NEXT: ret i1 [[CMP2]]
;
%x = add i32 %a, 3 ; thwart complexity-based canonicalization
%cmp1 = icmp sgt i32 %y, %x
%sel = select i1 %cmp1, i32 %y, i32 %x
%cmp2 = icmp sge i32 %x, %sel
ret i1 %cmp2
}
; smax(X, Y) != X --> X < Y
define i1 @ne_smax1(i32 %x, i32 %y) {
; CHECK-LABEL: @ne_smax1(
; CHECK-NEXT: [[CMP2:%.*]] = icmp slt i32 %x, %y
; CHECK-NEXT: ret i1 [[CMP2]]
;
%cmp1 = icmp sgt i32 %x, %y
%sel = select i1 %cmp1, i32 %x, i32 %y
%cmp2 = icmp ne i32 %sel, %x
ret i1 %cmp2
}
; Commute max operands.
define i1 @ne_smax2(i32 %x, i32 %y) {
; CHECK-LABEL: @ne_smax2(
; CHECK-NEXT: [[CMP1:%.*]] = icmp sgt i32 %y, %x
; CHECK-NEXT: ret i1 [[CMP1]]
;
%cmp1 = icmp sgt i32 %y, %x
%sel = select i1 %cmp1, i32 %y, i32 %x
%cmp2 = icmp ne i32 %sel, %x
ret i1 %cmp2
}
; Disguise the icmp predicate by commuting the max op to the RHS.
define i1 @ne_smax3(i32 %a, i32 %y) {
; CHECK-LABEL: @ne_smax3(
; CHECK-NEXT: [[X:%.*]] = add i32 %a, 3
; CHECK-NEXT: [[CMP2:%.*]] = icmp slt i32 [[X]], %y
; CHECK-NEXT: ret i1 [[CMP2]]
;
%x = add i32 %a, 3 ; thwart complexity-based canonicalization
%cmp1 = icmp sgt i32 %x, %y
%sel = select i1 %cmp1, i32 %x, i32 %y
%cmp2 = icmp ne i32 %x, %sel
ret i1 %cmp2
}
; Commute max operands.
define i1 @ne_smax4(i32 %a, i32 %y) {
; CHECK-LABEL: @ne_smax4(
; CHECK-NEXT: [[X:%.*]] = add i32 %a, 3
; CHECK-NEXT: [[CMP1:%.*]] = icmp slt i32 [[X]], %y
; CHECK-NEXT: ret i1 [[CMP1]]
;
%x = add i32 %a, 3 ; thwart complexity-based canonicalization
%cmp1 = icmp sgt i32 %y, %x
%sel = select i1 %cmp1, i32 %y, i32 %x
%cmp2 = icmp ne i32 %x, %sel
ret i1 %cmp2
}
; smax(X, Y) > X --> X < Y
define i1 @sgt_smax1(i32 %x, i32 %y) {
; CHECK-LABEL: @sgt_smax1(
; CHECK-NEXT: [[CMP2:%.*]] = icmp slt i32 %x, %y
; CHECK-NEXT: ret i1 [[CMP2]]
;
%cmp1 = icmp sgt i32 %x, %y
%sel = select i1 %cmp1, i32 %x, i32 %y
%cmp2 = icmp sgt i32 %sel, %x
ret i1 %cmp2
}
; Commute max operands.
define i1 @sgt_smax2(i32 %x, i32 %y) {
; CHECK-LABEL: @sgt_smax2(
; CHECK-NEXT: [[CMP1:%.*]] = icmp sgt i32 %y, %x
; CHECK-NEXT: ret i1 [[CMP1]]
;
%cmp1 = icmp sgt i32 %y, %x
%sel = select i1 %cmp1, i32 %y, i32 %x
%cmp2 = icmp sgt i32 %sel, %x
ret i1 %cmp2
}
; Disguise the icmp predicate by commuting the max op to the RHS.
define i1 @sgt_smax3(i32 %a, i32 %y) {
; CHECK-LABEL: @sgt_smax3(
; CHECK-NEXT: [[X:%.*]] = add i32 %a, 3
; CHECK-NEXT: [[CMP2:%.*]] = icmp slt i32 [[X]], %y
; CHECK-NEXT: ret i1 [[CMP2]]
;
%x = add i32 %a, 3 ; thwart complexity-based canonicalization
%cmp1 = icmp sgt i32 %x, %y
%sel = select i1 %cmp1, i32 %x, i32 %y
%cmp2 = icmp slt i32 %x, %sel
ret i1 %cmp2
}
; Commute max operands.
define i1 @sgt_smax4(i32 %a, i32 %y) {
; CHECK-LABEL: @sgt_smax4(
; CHECK-NEXT: [[X:%.*]] = add i32 %a, 3
; CHECK-NEXT: [[CMP1:%.*]] = icmp slt i32 [[X]], %y
; CHECK-NEXT: ret i1 [[CMP1]]
;
%x = add i32 %a, 3 ; thwart complexity-based canonicalization
%cmp1 = icmp sgt i32 %y, %x
%sel = select i1 %cmp1, i32 %y, i32 %x
%cmp2 = icmp slt i32 %x, %sel
ret i1 %cmp2
}